The present invention relates to a drive nut and drive screw for a seat adjuster and in particular to a nut and screw for a vehicle seat assembly that provides ease of assembly and low noise during operation.
In vehicle seat assemblies and, in particular, seat assemblies having power adjustment capability, it is desirable to provide an adjuster which produces low noise emissions during operation. Furthermore, it is necessary to provide an adjuster that can be easily assembled to reduce assembly time and errors.
Accordingly, it is an object of the present invention to provide a drive nut and drive screw for a vehicle seat adjuster that is both easy to assemble and produces low noise during operation.
It is an advantage of the present invention that the drive nut and mounting bracket are configured so that the nut is self aligning with the drive screw and the transmission assembly to prevent binding during operation of the seat adjuster.
It is a feature of the drive nut and its mounting bracket that the drive nut can be assembled with the bracket after the drive nut has been threaded onto the drive screw. This eliminates the cumbersome task of threading the screw into the drive nut at a time when major components of the seat are being assembled.
It is a further feature of the present invention to provide a four start drive screw that permits the motor to operate at a lower speed while providing the same operating speed of the seat adjuster. This reduces the noise transmitted from the motor, drive cable and transmission. It is yet another advantage that a four start screw with a rolled thread is straighter than either a one or three start screw with a rolled thread. The straighter screw shaft reduces drive nut vibration, further reducing the noise emission.
Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying drawings.